Visual Perceptual Deficits It’s More than an acuity issue

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Visual Perceptual Deficits It’s More than an acuity issue. Presented By: Dalita Meyer, OTR/L Avera St. Luke’s. The Brain: A Complex Machine. Its performance tends to degrade gracefully under partial damage - PowerPoint PPT Presentation

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Presented By: Dalita Meyer, OTR/LAvera St. Luke’s

Its performance tends to degrade gracefully under partial damage

In contrast, most programs and engineered systems are brittle: if you remove some arbitrary parts, very likely the whole will cease to function

It can learn (reorganize itself) from experience This means that partial recovery from damage is

possible if healthy units can learn to take over the functions previously carried out by the damaged areas

It performs massively parallel computations extremely efficiently

For example, complex visual perception occurs within less than 100 ms, that is, 10 processing steps

It supports our intelligence and self-awareness Nobody knows yet how this occurs

A transient ischemic attack (also called TIA or “mini stroke”) is one of the most important warning signs of future stroke

A TIA occurs when a blood clot blocks an artery that supplies blood to the brain

The symptoms of a TIA, which are temporary and may last a few minutes or a few hours, can occur alone or in combination

A TIA is a medical emergency, since it is impossible to predict if it will progress into a major stroke

If you or someone you know experiences these symptoms, get emergency help

Immediate treatment can save your life or increase your chance of a full recovery

Age: Over 55 years of age

High levels of cholesterol in blood test

Smoking

High blood pressure (hypertension)

Diabetes Obesity Sedentary lifestyle 

Injury caused by trauma to the skull or brain Caused by accidents, falls, assaults, traffic accidents Adults obtain TBI’s more frequently than any other

age group Children experience TBI’s due to accidental falls and

intentional abuse More likely to develop Alzheimer’s and Parkinson’s

later in life

Visual attention Oculomotor contol

- Provides perceptual stability

Visual Acuity - Provides clarity – ability to see details

Visual Field - Provides awareness of objects

Acuity

Ocular Motor Control

Visual Field Deficit

Unilateral Spatial Neglect

Ability to see detail and color

Acuity Tests

Contrast Tests

Reading Acuity Tests

Task Analysis

Corrective lenses Increase contrast – bright tape, paint bright labels, ligh walls

w/dark furniture, contrast light switches and electrical outlets

Solid colors for rugs, bedspreads, dishes, countertops Decrease clutter Bold tip pens, bold line paper Magnifiers Motion lights Teach compensatory skills with other senses

Subjective complaints – Interview Observe head and eyes Eye dominance Eye movements Task Analysis

Controlled and stabilized eye movement

Essential for near vision Complaint fatigue with reading, writing or close

work

Saccadic - Change the line of sight - Activated by attention

Rapid eye movements that change the line of sight

Patient calling out or point to letters from two columns printed on opposite sides of page

Provide vestibular movements in conjunction with demands of saccadic skills

Provide anchoring during reading tasks Control the density of the visual information being

presented

Body parts

Right/left discrimination

Provide tactile input – patient rub arm with rough cloth while name the body part

Practice particular tasks that reinforce body parts

Bilateral activities

Educate patient and family and train family how to assist with affected side

Changes in visual search caused by visual inattention

Prisms have improved this however there needs to be more studies if there is a carry over for ADL’s

Patching Flashing lights versus static stimuli Verbal, auditory and tactile cueing

Education for patient and family Compensatory strategies Educate on scanning with head and eye movements by

progression - Movements leading the eye from attended to

unattended space - Eye movements into the unattended space - Eye movements without the use of head movements Place all items for functional independence within the patient’s field of vision

Area of visual world that can be seen when looking straight ahead

Place objects commonly used on the side of the patient effected side

Provide verbal auditory and tactile cues to encourage patient to look to the affected

Practice worksheets as a treatment for scanning

Place items for functional independence within the patient’s field of vision

Educate patient and family about field loss – especially related to safety

Work on compensation techniques – i.e. tape, finger

Adopt a narrow search pattern confined to midline and sound side

Person scans very slowly towards deficit side Missing and/or “misidentifying” visual detail on the

“blind” side Reduced visual monitoring of the hand

The dog ran quickly to his master.

Viewer-based: ckly to his master.

Object-based: he og an ickly o is ster.

Delicious Eight

licious Fight

Reading Task

Scan Course

Telephone Number copy

Compensation requires conscious cognitive strategy

Must believe vision cannot be trusted on deficit side

Awareness allows client to develop “intellectual over-ride”

Left to right, clockwise counterclockwise

Develop strategies with the patient on how to take in visual information in an organized manner

Complete treatment activities such as crossing out target letters, mazes, puzzles, solitare card game

Locate items in a store found on a list Locate names, items and prices in the newspaper Locate names, number in a phone book

Anchoring or cueing the patients to where to begin the visual search – tape marker

Pacing or cueing the patient about the speed of response – for impulsive or erratic scanning

Control the density or spacing of objects Stack clothing in a consistent order

These patients have deficits in their ability to plan or complete motor actions that rely on semantic memory. They are able to explain how to perform an action, but unable to "imagine" or act out a movement such as "pretend to brush your teeth" or "pucker as though you bit into a sour lemon." The ability to perform an action automatically when cued, however, remains intact. This is known as automatic-voluntary dissociation. For example, they may not be able to pick up a phone when asked to do so, but can perform the action without thinking when the phone rings.

Patients have an inability to conceptualize a task and impaired ability to complete multistep actions. Consists of an inability to select and carry out an appropriate motor program. For example, the patient may complete actions in incorrect orders, such as buttering bread before putting it in the toaster, or putting on shoes before putting on socks. There is also a loss of ability to voluntarily perform a learned task when given the necessary objects or tools. For instance, if given a screwdriver, the patient may try to write with it as if it were a pen, or try to comb one's hair with a toothbrush.

Dressing apraxia is the inability to dress

Dressing apraxia can be due to ideomotor or ideational apraxia

The patient may not cognitively understand the demands of the dressing task (ideational) or has lost the appropriate motor plan to complete the task (ideomotor) or maintains the appropriate motor plan but is unable to access it (ideomotor)

For example, a patient with ideomotor apraxia understands that trousers are worn over their legs but cannot access the appropriate motor plan and therefore may put their arms through the legs

(from Greek praxis, an act, work, or deed) is the inability to execute learned purposeful movements, despite having the desire and the physical capacity to perform the movements. Apraxia is an acquired disorder of motor planning, but is not caused by incoordination, sensory loss, or failure to comprehend simple commands (which can be tested by asking the person to recognize the correct movement from a series). It is caused by damage to specific areas of the cerebrum.

Apraxia should not be confused with ataxia, a lack of coordination of movements; aphasia, an inability to produce and/or comprehend language; abulia, the lack of desire to carry out an action; or allochiria, in which patients perceive stimuli to one side of the body as occurring on the other. Developmental coordination disorder (DCD) is the developmental disorder of motor planning.

Non-verbal oral or buccofacial ideomotor apraxia resulting in difficulty carrying out movements of the face on demand. For example, an inability to lick one's lips or whistle.

The inability to draw or construct simple configurations, such as intersecting pentagons.

The loss of ability to have normal function of the lower limbs such as walking. This is not due to loss of motor or sensory functions.

Difficulty making precise movements with an arm or leg.

Difficulty moving the eye, especially with saccade movements that direct the gaze to targets

Difficulty planning and coordinating the movements necessary for speech.

Questions???